Subaru 2009 IMPREZA Service Manual page 346

COOLING
Step
26 CHECK POOR CONTACT.
Check for poor contact of ECM connector.
27 CHECK OPERATION OF RADIATOR FAN.
If the both radiator fans do not rotate at high
speed in the condition of step 2, check whether
the radiator sub fan is rotating.
28 CHECK GROUND CIRCUIT OF MAIN FAN
RELAY 2.
1) Remove the main fan relay 2 from A/C relay
holder.
2) Measure the resistance between main fan
relay 2 terminal and chassis ground.
Connector & terminal
(F27) No. 19 — Chassis ground:
29 CHECK POWER SUPPLY TO MAIN FAN RE-
LAY 2.
1) Turn the ignition switch to ON.
2) Measure the voltage between main fan relay
2 terminal and chassis ground.
Connector & terminal
(F27) No. 20 (+) — Chassis ground (–):
30 CHECK MAIN FAN RELAY 2.
1) Turn the ignition switch to OFF.
2) Remove the main fan relay 2.
3) Measure the resistance of main fan relay 2.
Terminals
(F27) No. 18 — (F27) No. 19:
31 CHECK MAIN FAN RELAY 2.
1) Connect the battery to terminals No. 20 and
No. 22 of the main fan relay 2.
2) Measure the resistance of main fan relay 2.
Terminals
(F27) No. 18 — (F27) No. 19:
Radiator Fan System
Check
Is there poor contact of ECM
connector?
Does the radiator sub fan
rotate?
Is the resistance less than 1 ? Go to step 29.
Is the voltage 10 V or more?
Is the resistance 1 M or
more?
Is the resistance less than 1 ? Go to step 23.
CO(H4SO)-12
Yes No
Repair the poor Repair the power
contact of ECM supply circuit to the
connector. main fuse box.
Go to step 20. Go to step 28.
Repair the open
circuit of harness
between main fan
relay 2 and chassis
ground.
Go to step 30. Repair the power
supply line.
Go to step 31. Replace the main
fan relay 2. <Ref. to
AC-39, Relay and
Fuse.>
Replace the main
fan relay 2. <Ref. to
AC-39, Relay and
Fuse.>